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Biomedical subjects

A Farrow

Publications and source records attributed to A Farrow.

At least 19 recordsLinked to original sources
PubMed2006

Pedicled genial osteotomy modification of the mandibular release access operation for access to the back of the tongue.

We report a modification of the operation of mandibular release or 'visor drop down'. It allows more accurate repositioning and more permanent fixation of the genioglossus, geniohyoid, and digastric muscles using a small anterior osteotomy. We hope that this more accurate and reliable repositioning will give improved outcomes in terms of speech, chewing, and swallowing.

Humans↗
PubMed2005

Frequent use of chemical household products is associated with persistent wheezing in pre-school age children.

BACKGROUND: In the UK and other developed countries the prevalence of asthma symptoms has increased in recent years. This is likely to be the result of increased exposure to environmental factors. A study was undertaken to investigate the association between maternal use of chemical based products in the prenatal period and patterns of wheeze in early childhood. METHODS: In the population based Avon Longitudinal Study of Parents and Children (ALSPAC), the frequency of use of 11 chemical based domestic products was determined from questionnaires completed by women during pregnancy and a total chemical burden (TCB) score was derived. Four mutually exclusive wheezing patterns were defined for the period from birth to 42 months based on parental questionnaire responses (never wheezed, transient early wheeze, persistent wheeze, and late onset wheeze). Multinomial logistic regression models were used to assess the relationship between these wheezing outcomes and TCB exposure while accounting for numerous potential confounding variables. Complete data for analysis was available for 7019 of 13, 971 (50%) children. RESULTS: The mean (SD) TCB score was 9.4 (4.1), range 0-30. Increased use of domestic chemical based products was associated with persistent wheezing during early childhood (adjusted odds ratio (OR) per unit increase of TCB 1.06 (95% confidence interval (CI) 1.03 to 1.09)) but not with transient early wheeze or late onset wheeze. Children whose mothers had high TCB scores (>90th centile) were more than twice as likely to wheeze persistently throughout early childhood than children whose mothers had a low TCB score (<10th centile) (adjusted OR 2.3 (95% CI 1.2 to 4.4)). CONCLUSION: These findings suggest that frequent use of chemical based products in the prenatal period is associated with persistent wheezing in young children. Follow up of this cohort is underway to determine whether TCB is associated with wheezing, asthma, and atopy at later stages in childhood.

Body Burden↗
PubMed2001

Clinical investigation of a true color scanning laser ophthalmoscope.

OBJECTIVE: To show true color scanning laser ophthalmoscope (SLO) images produced by simultaneously imaging the retina with red, green, and blue lasers. METHODS: Low-power red, green, and blue lasers were combined using fiber optics. By rapidly pulsing the lasers, each point on the fundus is illuminated by the 3 colors in quick succession, with the total power level being similar to that from a single laser. The reflected light is then decoded to extract the red, green, and blue color information and the true color fundus image is displayed live on a computer monitor. RESULTS: Comparison was made between the color SLO images from 5 patients and their digitized fundus photographs. The background fundus and retinal vasculature showed a similar appearance. The SLO gave better quality information in patients with ocular histoplasmosis, macular dystrophy, and optic disc drusen. By operating the color SLO in the indirect mode, macular edema could be clearly seen as lines and ridges surrounding the fovea. CONCLUSION: The color SLO offers all the advantages of the present commercially available monochromatic device, with the added advantage of true color representation of the fundus without increasing either imaging time or the level of exposure.

Adult↗
PubMed2000

Delayed conception and active and passive smoking. The Avon Longitudinal Study of Pregnancy and Childhood Study Team.

OBJECTIVE: To determine whether passive as well as active smoking by women or smoking by men is associated with delayed conception, after adjustment for confounding factors. DESIGN: Population study of couples expecting a baby. Logistic regression was performed to identify factors associated with delayed conception. SETTING: The Avon Health Authority area, United Kingdom. PATIENT(S): All couples expected to deliver between April 1991 and December 1992. INTERVENTION(S): Questionnaires administered early in pregnancy. MAIN OUTCOME MEASURE(S): Time taken to conceive, categorized as <6 months, 6-11 months, 1-3 years, and >3 years. RESULT(S): After correction for confounding factors, delayed conception was statistically significantly associated with both active smoking by the woman (odds ratio [OR] 1.23 [95% CI 0.98-1.49] for > 6 months and 1.54 [95% CI 1.19-2.01] for >12 months) and her exposure to passive smoking (OR 1.17 [95% CI 1.02-1.37] and 1.14 [95% CI 0.92-1.42]) compared with women with no exposure to tobacco smoke (referent). Heavy smoking by men was independently associated with delayed conception. In active smokers, the effect increased with the number of cigarettes. CONCLUSION(S): Smoking by men and passive and active smoking by women are associated with delayed conception.

Adult↗
PubMed2000

Increasing paternal age is associated with delayed conception in a large population of fertile couples: evidence for declining fecundity in older men. The ALSPAC Study Team (Avon Longitudinal Study of Pregnancy and Childhood).

The impact of male age on fecundity remains controversial. Here, a large population study was used to investigate the effect of paternal age on time to conception. All couples in the Avon Health district expecting a baby between 1 April 1991 and 31 December 1992 were eligible. Questionnaires completed by both the man and the woman at 18 weeks gestation covered specific fertility factors, e.g. parity, paternity, cohabitation and oral contraception; and non-specific factors, e.g. educational achievement, housing, cigarette smoking, alcohol consumption, obesity. Logistic regression was used to identify factors independently related to conception in < or =6 or < or =12 months. Of 8515 planned pregnancies, 74% were conceived in < or =6 months, 14% in the second 6 months and 12% after more than a year. Nine variables, including the age of the woman, were independently related to time to conception. After adjustment for these, the likelihood of conception within 6 or 12 months was lower in older men. Compared to men <25 years old, the adjusted odds ratios (95% confidence interval) for conception in < or =12 months were 0.62 (0.40, 0.98), 0.50 (0.31, 0.81) and 0.51 (0.31, 0.86) in men aged 30-34, 35-39 and > or =40 years respectively.

Adult↗
PubMed1999

Diarrhoea and nitrogen oxides.

It is hypothesized that higher indoor nitrogen dioxide levels cause diarrhoea in infants and that this is the result of a direct action of oxides of nitrogen on the gut. This hypothesis is tested by reviewing the reported association between methaemoglobin and diarrhoea in children and two recent reports on indoor air and diarrhoea in infants. The collection of further empirical data is now needed. Studies which measure indoor levels of nitrogen dioxide could usefully collect data on infants symptoms that are not exclusively respiratory. Similarly, studies which are collecting diary information on children's health symptoms should consider collecting data on indoor air quality with respect to the oxides of nitrogen.

Air Pollution, Indoor↗
PubMed1998

Birthweight of term infants and maternal occupation in a prospective cohort of pregnant women. The ALSPAC Study Team.

OBJECTIVE: To study the relation between birthweight of term infants and maternal occupation. METHODS: Information on job titles since the age of 16, and sociodemographic and other lifestyle factors were obtained by means of questionnaires as part of the Avon longitudinal study of pregnancy and childhood (ALSPAC), from a cohort of 14,000 pregnant women. The British 1990 standard occupational classification was used to code jobs within nine major job groups. RESULTS: For 9282 women who delivered term infants and reported a job for the relevant period, there was a significant difference in mean birthweight among the nine major job groups. A 148 g difference was found between the mean birthweight of infants born to women with professional occupations and those with plant and machine operative jobs. Multiple regression analysis adjusted for sex of infant, parity, maternal height, smoking, caffeine consumption, and race. After adjustment the maternal job was no longer significantly associated with birthweight. CONCLUSION: Despite the absence of a significant association between birthweight and job after adjustment, there were several findings which agreed with publications on maternal occupation and pregnancy outcome. The major job groups with the lowest birthweights included the following jobs; metal forming or welding, electric or electronic work, jobs in the textile trade, and assembling and working with equipment (mobile and stationary). The lack of an association may indicate that the study was of insufficient power to detect a small difference; it may indicate the presence of confounding variables that were not adjusted for or it may indicate that no association exists.

Adolescent↗
PubMed1997

An investigation of the effect of paternal occupation group at conception on birth weight and gestational age. ALSPAC Study Team of Pregnancy and Childhood.

The occupational histories of fathers were collected prospectively as part of the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC), and were used to investigate the association of paternal job title with a baby's birth weight and gestational age. The analysis cohort consisted of 4,795 singleton live-born babies whose fathers responded fully to questionnaire items regarding occupational history. Jobs were coded using the British Standard Occupational Codes and classified into nine major occupational groups. A 73-gram difference (95% CI: 0.16, 145.17) was found between the mean birth weight of full-term babies born of professional fathers (3,543 gm) and of fathers working in craft and related occupations (3,470 gm). This difference decreased and lost significance after controlling for sociodemographic variables. No difference was found in the mean birth weight of preterm babies, or in the rate of preterm delivery, when analyzed by paternal occupation at conception. Our results suggest that when important sociodemographic variables are known, the father's job title alone may not be a useful predictor of birth weight or preterm delivery.

Birth Weight↗
PubMed1997

Elevation of homocysteine and excitatory amino acid neurotransmitters in the CSF of children who receive methotrexate for the treatment of cancer.

PURPOSE: Folate deficiency, either by diet or drug, increases plasma homocysteine (Hcy). Hcy damages cerebrovascular endothelium, and hyperhomocysteinemia is a risk factor for stroke. Hcy is metabolized to excitatory amino acid (EAA) neurotransmitters, such as homocysteic acid (HCA) and cysteine sulfinic acid (CSA), which may cause seizures and excitotoxic neuronal death. We postulated that excess Hcy and EAA neurotransmitters may partly mediate methotrexate (MTX)-associated neurotoxicity. PATIENTS AND METHODS: In this retrospective analysis, we used high-performance liquid chromatography (HPLC) to measure Hcy, HCA, and CSA in CSF from two groups of children: (1) a control group of patients with no MTX exposure, and (2) a treatment group of patients who had received MTX no more than 7 days before a scheduled lumbar puncture. RESULTS: The treatment group had a significantly (P = .0255) greater concentration of Hcy in CSF (0.814 micromol/L +/- 0.215 [mean +/- SEM], n = 23) than the control group (0.210 micromol/L +/- 0.028, n = 34). HCA and CSA were not detected in CSF from control patients (n = 29); however, MTX caused marked accumulation of CSF HCA (119.1 micromol/L +/- 32.0, n = 16) and CSA (28.4 micromol/L +/- 7.7, n = 16) in the treatment group. Patients with neurologic toxicity at the time of lumbar puncture had many of the highest concentrations of Hcy, HCA, and CSA. CONCLUSION: These data support our hypothesis that MTX-associated neurotoxicity may be mediated by Hcy and excitotoxic neurotransmitters.

Antimetabolites, Antineoplastic↗
PubMed1996

The repeatability of self-reported exposure after miscarriage. ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood.

BACKGROUND: The Avon Longitudinal Study of Pregnancy and Childhood is a prospective study of women who were resident in Avon and who were expected to deliver a baby between April 1991 and December 1992. METHODS: The study provided an opportunity to test the repeatability of responses from 220 women who experienced a miscarriage and who reported exposure to occupational substances and common household products and appliances in two questionnaires. The first questionnaire was completed in the early part of the pregnancy and the second after the miscarriage. Women were asked to score their frequency of exposure on a five-point scale from 'daily' to 'never'. Their responses were analysed to assess the degree of agreement between replies to identical questions in the two questionnaires using the kappa statistic. A new frequency variable was created which compared the replies for the two questionnaires; this was analysed for all exposures by cross-tabulation with possible explanatory variables (age of mother, social class, history of miscarriage and the time lag between questionnaires). RESULTS: In general there was good agreement in the reported exposures to 48 substances and products. The results showed a small and consistent pattern of reporting exposures less frequently in the second questionnaire, i.e. after miscarriage. This was not explained by the analysis of possible confounding variables. Given the literature, the authors had expected to find a shift in the opposite direction. CONCLUSION: The study reinforces the need to be cautious when using the results from single surveys of retrospective self-reported exposure.

Abortion, Spontaneous↗
PubMed1996

Intensive oral methotrexate protects against lymphoid marrow relapse in childhood B-precursor acute lymphoblastic leukemia.

PURPOSE: To describe the use of combination chemotherapy, including divided-dose oral methotrexate (dMTX), for children with B-precursor acute lymphoblastic leukemia (ALL). dMTX produced prolonged MTX exposure on an outpatient basis. PATIENTS AND METHODS: Two hundred forty-three patients were treated from January 1986 to May 1992. dMTX was given weekly during consolidation and biweekly for the first 16 months of continuation therapy with mercaptopurine (6-MP) and asparaginase (L-ASP). Initially, etoposide (VP-16) and cytarabine (Ara-C) pulses were included. Treatment continued for 30 months with single-dose weekly MTX replacing dMTX during continuation, part 2. Unexpected acute neurotoxicity was eliminated by the addition of leucovorin. VP-16 and Ara-C were omitted in the face of acute myelogenous leukemia (AML). RESULTS: Two hundred thirty-nine patients entered remission: 16 had a lymphoid marrow relapse, two each with testicular or CNS relapse; 19 a CNS relapse; 16 secondary AML; three other second malignancies; two withdrew for transplant; three died in remission; 16 withdrew because of noncompliance, and nine withdrew with toxicity. Event-free survival (EFS) at 4 years was 73 +/- 4%; 81 +/- 4% for 150 patients with better risk features and 60 +/- 7% for 93 with high-risk features. Lymphoid marrow relapse-free survival in the standard- and high-risk patients was 94 +/- 3% and 86% +/- 6%, respectively. The most common adverse event was secondary AML in the standard-risk group and isolated CNS relapse in the high-risk group. CONCLUSION: This therapy produced an overall EFS similar to other published regimens, but the pattern of failures is very different, with few patients having a lymphoid marrow relapse. These data suggest that highly effective therapy for children with ALL can be delivered on an outpatient basis using a regimen featuring repetitive dMTX.

Administration, Oral↗
PubMed1995

Occupational and environmental exposures and myelodysplasia: a case-control study.

A case-control study of newly diagnosed myelodysplastic syndrome patients investigated lifetime exposures through occupation, environment or hobby by questionnaire, structured and semi-structured interview. The exposure histories of 400 individually matched pairs were compared. Increased or possibly increased odds ratios were observed for radiation (2.05, 95% confidence interval 1.16-3.76), halogenated organics (1.57, 0.97-2.57), metals (1.40, 0.99-2.00), several specific radiation exposures and individual chemicals and for childlessness (1.46, 1.01-2.11). Since myelodysplasia generally carries a poor prognosis, whether or not individuals convert to leukaemia or to other cancer, these findings add to previous reports of exposures implicated in the aetiology of leukaemia and add to the case for minimizing exposures to radiation and halogenated organics.

Adolescent↗
PubMed1990

Audit of amniocentesis from a district general hospital: is it worth it?

OBJECTIVE: To audit all mid-trimester amniocenteses performed by obstetricians at a district general hospital to see whether experience improved the outcome. DESIGN: Retrospective review of medical records. SETTING: Royal Gwent Hospital, south Wales. SUBJECTS: All 469 amniocenteses carried out in 1985-7. OUTCOME MEASURES: Number of attempts at withdrawal of amniotic fluid; number with bloodstained liquor; and number of subsequent miscarriages, terminations, and congenital abnormalities. RESULTS: Of the 469 amniocenteses, 411 were performed by one obstetrician, and initial comparisons with those performed by the rest of the hospital team showed no significant differences in outcome of pregnancy. The main difference between the two groups was in the number of attempts at withdrawal of amniotic fluid and the number with bloodstained liquor. The single obstetrician failed to obtain amniotic fluid on 1% of occasions compared with 10% for the other operators by the end of the second attempt. The costs of carrying out the audit were considerable. The review of fewer than 500 case records cost the equivalent of 2000 pounds in staff time and took over 200 hours to complete, equivalent to 63 sessions of one person's time. CONCLUSIONS: The audit was useful in that it provided information on complication rates, which could be compared with published data, and comparisons between obstetricians who perform large and small numbers of procedures. IMPLICATIONS: For an individual's practice the monitoring of amniocentesis should not be continuously carried out and subsequent audits should tackle other common procedures. When an audit is attempted the health service should provide adequate support to clinicians for this purpose.

Amniocentesis↗
PubMed1989

Non-admission or non-invitation? A case-control study of failed admissions.

OBJECTIVE: To examine the causes of non-admission to hospital. DESIGN: Validation of published rates of non-admission by examination of medical records, followed by a case-control study of non-attenders (cases) and attenders (controls). SETTING: General hospital. SUBJECTS: 246 Patients (cases in the case-control study) booked for admissions in four specialties (general surgery, gynaecology, otorhinolaryngology, and trauma and orthopaedics) during April, May, and June 1987 who were not admitted for reasons that seemed to be attributable to the patients. Controls comprised 167 patients admitted to the same specialty on the same day. RESULTS: The validation of administrative records indicated that it is unusual for patients to fail to present for admission without advising the hospital beforehand; this occurred in only 1-3% of all bookings. Information on the circumstances of non-admission and clinical and personal details were collected by means of a six page questionnaire completed by the patients. The case-control study showed that those not admitted were younger and had been on the waiting list longer. Otherwise only small differences were found in the social and clinical characteristics. CONCLUSIONS: Despite a common tendency to blame patients for non-admission, factors due to patients are fairly unimportant.

Age Factors↗
PubMed1989

Non-attendance or non-invitation? A case-control study of failed outpatient appointments.

OBJECTIVE: To determine the causes of non-attendance at new outpatient appointments. DESIGN: Case-control study of non-attenders and attenders. SETTING: Outpatient department of a general hospital. SUBJECTS: All non-attenders (n = 277) for first outpatient appointments in six specialties during a three month period were included. Controls (n = 135) were the attenders who followed every second non-attender; thus they attended the same consultant on the same day that the non-attenders were expected. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Information on the clinical problem, difficulties in attending the hospital, and reasons for non-attendance from the questionnaire were coded and classified. Non-attenders had received shorter notice of their appointment than attenders (14% v 1% had received three days' notice or less). There were small differences in the seriousness of patients' clinical condition. CONCLUSIONS: Client factors are less important than aspects of the service in explaining non-attendance at outpatient appointments.

Adolescent↗